Like the Akashiya Sai and Akashiya Thin Line pens I reviewed previously, both the Pentel and Kuretake pens have actual hairy brush tips, not formed felt tips. Unlike the others I reviewed previously, however, which are ready to use upon uncapping, both the Pentel and Kuretake brush pens have reservoirs of dye ink that must be punctured before first use. They are identical in this regard: A small ring between the reservoir half of the pen and the brush half is removed, and when the two parts are screwed back together, the reservoir is punctured, allowing ink to flow to the brush. Both pens have an area on the reservoir barrel that can be squeezed to force more ink into the brush, but I found that gravity alone usually kept a steady flow going while sketching and painting. (Use care when removing or replacing the caps on both of these pens – if you inadvertently squeeze the barrel while doing this, you may find yourself with ink on your lap!)

I should qualify “steady flow,” because I found that some colors of the Kuretake flowed more consistently than others. I have four colors, and the purple is practically a gusher, while the other three colors flow more consistently. (I have only one color of the Pentel, so I couldn’t make a comparison with this brand.)

If you’re familiar with Kuretake waterbrushes (also marketed in the U.S. as Niji waterbrushes), the design of the Kuretake Brush Writer will give you déjà vu. I wouldn’t be surprised if the brush tip is made of identical material. And although I haven’t tried this myself, I’m guessing that the ink reservoir, when empty (or emptied), can be refilled with water (or diluted ink) and the pen used just like a waterbrush.

One significant difference between the Akashiya pens reviewed previously and the Pentel and Kuretake brush pens reviewed here is that the latter are both refillable with ink cartridges. Dick Blick carries refills for the Pentel. When I asked JetPens.com whether refills were available for the Kuretake, I was told that they are, but JetPens does not carry them. However, they might consider offering them in the future if enough customers are interested. (Knowing that these pens are refillable makes me feel somewhat less guilty about the landfill I’m personally filling with all the disposable pens I’ve tossed in my lifetime.)

Enough about mechanics – let’s get to the good stuff. Both the Pentel and Kuretake brush tips have a relatively wide range of sensitivity for synthetic brushes. Both were designed for Asian calligraphers, so they are both capable of producing nice variations in thick and thin lines, but I was able to get a narrower line with the Pentel.

The biggest difference between these two competing products is the way the ink interacts with various paper types. I tried them on three: a Stillman & Birn Alpha sketchbook (100 lb.), a Stillman & Birn Delta sketchbook (180 lb.), and a Global Art Materials Hand Book (a somewhat toothy, lightweight paper that usually takes washes of water-soluble pens and pencils well).

On the heavyweight Delta paper, both inks performed nicely, as I expected (since every medium I’ve tried on the Delta paper looks beautiful). Colors were rich, and washes were even (well, as even as I could make them… the variable of the operator is always present). But on the Alpha and Hand Book papers, the Pentel ink feathered and looked grainy, while the Kuretake ink looked the same as it did on the heavier paper.

Pentel on Hand Book

Pentel on S & B Delta

Another important difference is the color range. The Pentel range is what I would call “basic” – three each of blues and greens, only one red – 18 total. The 24-color Kuretake range includes five each of greens and blues, three reds, two yellows and several bright hues (that I would trade in for a few more earthy tones if I could).

One probably minor difference: The Pentel is packaged for western markets, so the packaging and insert are in English. Alas, the Kuretake packaging information is in Japanese only (although the pen itself has a band around it with basic operational instructions in English). From the illustrations, I’m guessing that I’m missing only more detailed operational instructions, or perhaps care information, but I also see some “caution” symbols, so who knows what vital bits I’ll never read?

(When I was in elementary school, many of my Japanese American peers were “forced” by their parents to attend Japanese language school so that they would learn the language of their ancestors. Back then, I was always grateful that my parents didn’t make me give up my Saturdays that way, and those peers considered me lucky. As an adult, I have deeply regretted my Japanese illiteracy, especially in regard to reading packaging information on art materials.)

Kuretake on Hand Book

Kuretake on Delta

Overall, I’d say the Kuretake Brush Writer has a slight edge over the Pentel Color Brush, mainly because of the Pentel’s feathering on lighter-weight papers and its narrower color range. But the thinner brush tip on the Pentel is a strong point in its favor. For my money, though, I think both the Akashiya Sai and Akashiya Thin Line pens make a more variable brush line than either the Pentel or the Kuretake.Oct. 8, 2012, addendum: If you are traveling to high altitudes, leave these reservoir-type brush pens at home! Or at least don't open a pen cap over your sketchbook. I learned this lesson the hard way.